1. Field of the Invention
The present invention relates generally to syringes and containers for measured dosages of a liquid medication.
2. Description of the Prior Art
The terms xe2x80x9cmedication errorxe2x80x9d, xe2x80x9cadverse drug reactionxe2x80x9d, and xe2x80x9cadverse drug event are used frequently in the literature and have different meanings. The National Coordinating Council for Medication Error Reporting and Prevention defines medication error as xe2x80x9cany preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the health care professional, patient or consumer. Such events may be related to professional practice, health care products, procedures, and systems including prescribing; prescribing, order communication; product labeling; packaging; and nomenclature; compounding; dispensing; distribution; administration; education; monitoring; and use.
The World Health Organization defines an Adverse Drug Reaction (ADR) as xe2x80x9cany noxious, unintended, and undesired, effect of a drug which occurs at doses used in humans for prophylaxis, diagnosis, or therapy.xe2x80x9d This definition excludes among other things, adverse events due to errors in drug administration or non-compliance (taking more or less of a drug than the prescribed amount. The term Adverse Drug Event (ADE) is also used and unlike the ADR definition, does include errors in administration.
Several studies have demonstrated the high incidence of medication errors and the sometimes fatal results. For example, a Harvard Medical Practice Study surveyed 30,000 hospitalizations in several New York hospitals and found 3.7% of the patients experienced serious, disabling medical injuries, with 45% of them due to errors, see Leape, L., et al., xe2x80x9cSystems Analysis of Adverse Drug Events,xe2x80x9d Journal of the American Medical Association, Jul. 5, 1995, Vol. 274, No.1, pp.35-43. Also, a death certificate study found a greater than two-fold increase in deaths caused by medication errors between 1993, during which 7,391 people died, and 1983, when 2,876 patients died from medication errors, see Phillips, D. P., et al., xe2x80x9cIncrease in U.S. Medication-Error Deaths Between 1983 and 1993,xe2x80x9d The Lancet, Feb. 28, 1998, Vol. 351, No. 9103. Another report estimates that 6.5 ADE""s per 100 admissions, as well as an additional cost of $2,000 per adverse drug event for a hospitalized patient, excluding malpractice costs or cost of injury to the patient. Furthermore, while most ADE""s are a result of errors at the ordering stage, many occurred at the administering stage, as estimated by the study, see Bates, D. W., et al., xe2x80x9cIncidence of Adverse Drug Events and Potential Adverse Drug Events,xe2x80x9d Journal of the American Medical Association, Jul. 5, 1995, Vol. 274, No. 1, pp. 29-30. In addition, in large analysis insurance claims, injuries due to drugs were the most frequent cause of a procedure-related malpractice claim, see Leap, et al., 1995, JAMA, supra, and accounted for the highest total of expenditures of any type of procedure-related injury, see Bates, et al., 1995, JAMA, supra. A study by Lazarou, et al. study found between 76,000 and 106,000 deaths were caused by ADR""s, see Lazarou, J. et al., xe2x80x9cIncidence of adverse Drug Reactions in Hospitalized Patientsxe2x80x9d, JAMA, Apr. 15, 1998, Vol. 279, no. 15, pp. 1200-1205.
From a pediatric standpoint, a four-year study that investigated patterns of medication errors in neonatal and pediatric intensive care-units is instructive. Researchers found an error rate of 14.7% with one medication error occurring for every 6.8 admissions. The study found that while the percentage breakdown varied, all health care providers: physicians, nurses, and pharmacists, were responsible, see Raju TNK, et al., xe2x80x9cMedication Errors in neonatal and pediatric intensive care units,xe2x80x9d The Lancet, 1989, August. 12, pp. 374-376.
A 1993 study form the University of Wales clearly illustrates the complexity physicians face and the potential for medication error. Resident pediatrician""s pediatric advanced knowledge was evaluated following participation in a rigorous training program. The results reflected the difficulty faced by health care practitioners: only 52% could provide the correct dosage of epinephrine to be administered to a child during cardiac arrest, without using a reference text, see Buss, PW, et al., xe2x80x9cA Survey of basic resuscitation knowledge among resident pediatricians,xe2x80x9d Archive of Disease in Childhood, 1993, 68:75-8.
Human error is also not limited to physicians. A test administered to 100 registered nurses that assessed only mathematical calculating ability and involved questions concerning oral, intramuscular, and intravenous drugs yielded similar distressing results. The mean error rate was 19% on intramuscular/subcutaneous calculation questions, 36% on oral medication and 48% for intravenous drug delivery, see Bindler, et al., xe2x80x9cMedication calculation ability of registered nurses,xe2x80x9d Image: Journal of Nursing Scholarship, 1991, 23:331-224.
Medication errors include dose miscalculation, improper dosage delivery, and accidental administration of the wrong drug. While hospitals have voluntary reporting system in place, research has shown them to be inaccurate. A study of a voluntary system that uncovered only one medication errors per 1,000 drug orders, revealed an actual error rate of 32 per 1,000 medication errors, see Anderson, J. G., et al., xe2x80x9cEvaluating the Potential Effectiveness of Using Computerized Information Systems to Prevent Adverse Drug Events,xe2x80x9d AMIA, Inc., 1997, pp. 228-232. The cost of ADR""s and ADE""s is tremendous. While Anderson, et al. estimates that ADE""s annually result in 1,400 to 4,656 days of extra hospitalization with excess hospital costs ranging from $1.6 million to $5.5 million, U.S. Pharmacopoeia (USP) calculates ADE""s cost approximately $400 million per year in the U.S., excluding malpractice costs or cost of injury to the patient.
One attempt to reduce ADR""s and ADE""s has been to use prefilled syringes to avoid the risk of misidentification, and contamination. However, using a prefilled syringe still requires a physician or nurse to perform a mathematical calculation to convert between a patient""s height or weight to the volume of drug to be administered. In addition, using prefilled syringes necessitates having separate syringes for each drug that may be administered to a patient. Furthermore, for storing a given volume of a liquid medication, prefilled syringes are both awkward to store and require a great deal of space to store, when compared storing a liquid medication in one or more vials.
It is therefore an object of the present invention to provide a drug delivery system that reduces the possibility of adverse drug events.
It is another object of the present invention to provide a drug delivery system that avoids the need to perform a mathematical calculation to determine the amount of medication to be administered to an individual.
It is yet another object o the present invention to provide a drug delivery system that may be used to administer a number of medications quickly and easily.
It is yet another object of the present invention to provide a drug delivery system that may be used with existing vials for drugs.
According to a first broad aspect, the present invention provides syringe comprising a syringe barrel having a plurality of non-volumetric measuring indicia thereon.
According to a broad second aspect, the present invention provides a container comprising: at least one chamber; a plurality of non-volumetric measuring indicia on the at least one chamber; and an opening control device in the at least one chamber for allowing liquid contained in the at least one chamber to be withdrawn from the at least one chamber.
Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.